This invention relates to an antenna unit and a feeding component included therein, particularly, to a satellite signal receiving antenna unit for receiving a circular polarized wave such as a satellite radio broadcast.
A GPS (Global Positioning System) receiving antenna is currently known as an example of an antenna for receiving a radio wave from an artificial satellite. As the GPS receiving antenna, what is called a patch antenna is used, for example. The patch antenna has a ceramic board, which is an insulating material, with a pair of main surfaces On one of the main surfaces of the ceramic board, a ground electrode is provided. On the other of the main surfaces of the ceramic board, a receiving electrode and a feeding pin are provided. The feeding pin is used for supplying a receiving signal to an external circuit.
Recently, it is propelled to execute a radio broadcast and so on using a circular polarized wave transmitted from the artificial satellite. To receive the radio broadcast, what is called a satellite radio broadcast receiving antenna is used.
The satellite radio broadcast receiving antenna includes a feeding component and a metal plate (or a ground electrode) on which the feeding component is mounted. The feeding component includes a feeding line and an attaching member for supporting the feeding line against the metal plate.
The attaching member has a pair of fixing tongues which has locking hooks and protrudes downward. On the other hand, the metal plate provides a pair of locking aperture to partly receive the fixing tongues. When the attaching member is mounted on the metal plate, the fixing tongues are partly inserted in the locking aperture and the locking hooks engage with edges defining the locking apertures. As a result, the attaching member is fixed to the metal plate. In this time, the locking hooks are projected downward from a rear surface of the metal plate.
The feeding component is connected to a circuit board which is placed on the rear surface of the metal plate. To miniaturize the antenna unit, it is desirable that the circuit board is located to be close to the rear surface of the metal plate. However, as mentioned above, the locking hooks of the attaching element are projected from the rear surface of the metal plate. Accordingly, it is necessary to locate the circuit board to avoid collision with the locking hooks projected from the rear surface of the metal plate. Therefore, the satellite radio broadcast receiving antenna has a problem that the circuit board has limited shape and its mounting area is small.
It is therefore an object of this invention to provide a feeding component having an attaching member which can be attached to a metal plate without projecting any parts thereof.
Another object of this invention is to provide an antenna unit having the feeding component mentioned above.
Other objects of this invention will become clear as the description proceeds.
According to an aspect of this invention, an antenna unit comprises a first metal plate which serves as a ground electrode and which has a main surface, a rear surface and a pair of cut and raised parts raised from the main surface at both ends of the first metal plate. A second metal plate is opposite to the main surface of the first metal plate. A feeding component is mounted on the main surface of the first metal plate and has a wire and an attaching member made of resin. The attaching member supports the wire against the first metal plate. The attaching member has a pair of engaging parts at both ends thereof. The engaging parts are engaged with the cut and raised parts to attach the attaching member to the first metal plate without projecting of any parts of the attaching member from the rear surface of the first metal plate.
In the antenna unit, the engaging parts may comprise a pair of locking hooks partly inserted into said cut and raised parts. Alternatively, on the condition the cut and raised parts have catches facing each other, the engaging parts may provide hollows for receiving the catches. Furthermore, on the same condition mentioned above, the engaging parts may provide a pair of steps for engaging with the catches.
According to another aspect of this invention, a feeding component is for mounted on a main surface of a metal plate having a pair of cut and raised parts raised from the main surface at both ends of the metal plate. The feeding component comprises a wire and an attaching member made of resin. The attaching member is for supporting the wire against the metal plate. The attaching member has a pair of engaging parts at both ends thereof. The engaging parts are engaged with the cut and raised parts without projecting from a rear surface of the metal plate.
In the antenna unit, the engaging parts may comprise a pair of locking hooks which can be partly inserted into the cut and raised parts. Alternatively, on the condition that the cut and raised parts have catches facing each other, the engaging parts may provide a pair of hollows which can receive the catches. Furthermore, on the same condition mentioned above, the engaging parts may provide a pair of steps which can engage with the catches.
Referring to
In
The first metal plate 21 is made of metal material and shaped into a rectangular flat plate. The first metal plate 21 is attached to a lower cover 24. On the other hand, the second metal plate 22 is made of metal material and attached to an upper cover 25. The lower cover 24 and the upper cover 25 are assembled to form an internal space which contains the first metal plate 21, the pair of the feeding components 23 and the second metal plate 22.
As illustrated in
The feeding line 31 has a horizontal part which is supported by the attaching member 28 against a main surface of the first metal plate 21 to be apart from the first metal plate 21.
In the satellite radio broadcast receiving antenna having the structure mentioned above, the feeding components 23 are arranged so that their horizontal parts are perpendicular to each other and thereby good receiving characteristics are obtained regarding to both of right and left circular polarized waves. Accordingly, the feeding lines 31 of the feeding components 23 are attached to the attaching members 28 in symmetrical arrangement. In other words, two types of the feeding components 23 having symmetrical arrangements are necessary to assemble the satellite radio broadcast receiving antenna.
The insert molding, which is used for integrating the feeding line 31 with the attaching member 28, raises manufacturing cost of the satellite radio broadcast receiving antenna. Especially, in a case where two of the feeding components 23 having symmetrical arrangements are necessary to deal with the right and the left circular polarized waves, the insert molding further rises the manufacturing cost because two types of insert molding dies are necessary.
To solve the problems mentioned above, the applicants have already proposed a satellite signal receiving antenna unit which is made by a technique that either of the symmetrical feeding components 23 can be obtained by changing bending direction of a feeding line and thereby the manufacturing cost is considerably reduced. Such an antenna unit is disclosed in Unexamined Japanese Patent Application Publication (JP-A) No. 2005-20644.
The feeding line 2 has a shape bent at two points on the square. Accordingly, the feeding line 2 has a base end portion 2a bent in a vertical direction, a supporting portion 2b continuing on the base end portion 2a and extending on a horizontal plane, and a feeding portion 2c bent at a right angle with the supporting portion 2b on the horizontal plane.
At the middle of the first wire receiving groove 3a, a through hole 3c is bored through the attaching member 3 along the vertical direction. The through hole 3c is for receiving the base end portion 2a of the feeding line 2. The base end portion 2a inserted into the through hole 3c may be connected to a circuit board (not shown) to serve as an signal output electrode of the feeding line 2.
A plurality of tiny projections 3d is formed on inner wails defining the first wire receiving groove 3a of the attaching member 3. The tiny projections 3d press and hold the supporting portion 2b put into the first wire receiving groove 3a to prevent the supporting portion 2b of the feeding line 2 from falling away from the first wire receiving groove 3a. Thus, the tiny projections 3d allow the feeding line 2 to be fixed to the attaching member 3 without extra parts.
Referring to
After the feeding component 1 is mounted on the first metal plate 4, a circuit board (mentioned later) is located on a rear surface of the first metal plate 4. The base end portion 2a of the feeding line 2 is partially projected from the rear surface of the metal plate 4 and connected to the circuit board by solder.
As mentioned above, the locking hooks 5a are projected from the rear surface of the first metal plate 4 as shown in
Thus, the feeding component 1 has a problem of limiting a mounting area of a circuit board.
Referring to
The feeding component 40 has a feeding line (or a feeding probe) 42 made of metal and an attaching member 43 made of resin.
The feeding line 42 has a shape bent at two points on the square. Accordingly, the feeding line 42 has a base end portion 42a bent in a vertical direction, a supporting portion 42b continuing on the base end portion 42a and extending on a horizontal plane, and a feeding portion 42c bent at a right angle with the supporting portion 42b on the horizontal plane. The supporting portion 42b may be called a feeding portion together with the feeding portion 42c.
The attaching member 43 is a molding body having an almost rectangular parallelepiped shape. At the upper side of the attaching member 43, a first wire receiving groove 43a for receiving the supporting portion 42b of the feeding line 42 is formed along a longitudinal direction. At one of ends of the first wire receiving groove 43a, a second wire receiving groove 43b perpendicular to the first wire receiving groove 43a is formed to correspond to the feeding portion 42c perpendicular to the supporting portion 42b.
At the other end of the first wire receiving groove 43a, a through hole 43c is bored through the center of the attaching member 43 along the vertical direction. The through hole 43c is for receiving the base end portion 42a of the feeding line 42. The base end portion 42a inserted into the through hole 43c may be connected to a circuit board (not shown) to serve as an signal output electrode of the feeding line 42.
The first metal plate 50 has a pair of cut and raised parts 51 raised at a side of the attaching member 43 (or its main surface) at both ends. In other words, the cut and raised parts are raised from the main surface of the first metal plate 50. On the other hand, the attaching member 43 has locking hooks 432 at both ends thereof. The locking hooks 432 are partially insert into (or engage with) the cut and raised parts 51 without protruding from a rear surface of the first metal plate 50. At any rate, the locking hooks 432 serves as engaging means for engaging with the cut and raised parts.
Thus, the first metal plate 50 provides the cut and raised parts 51 to receive the feeding component 40 while the feeding component provides the locking hooks 432 locked to the cut and raised parts 51 at the position that the locking hooks 432 are not protrude from the rear surface of the first metal plate 50. Therefore, differently from the conventional satellite signal receiving antenna (see
According to the structure mentioned above, the rear surface of the first metal plate 50 is flat except for the base end portion 42a, which is connected to the circuit board by solder, of the feeding line 42. Thus, the feeding component 40 (or the attaching member 43) has no effect on the circuit board located on the rear surface of the first metal plate 50 regarding size, shape and/or mounting area.
Referring to
The first metal plate 50A has a pair of cut and raised parts 51 with catches 51a facing each other. On the other hand, the feeding component 40A provides hollows for receiving the catches 51a. That is, the feeding component 40A is similar to the feeding component 40 illustrated in
The feeding component 40A is mounted on the first metal plate 50A by putting the catches 51a of the cut and raised parts 51 of the first metal plate 50A into the hollows 433 of the feeding component 40A.
Putting the catches 51a of the cut and raised parts 51 into the hollows 433 may be implemented by elastic deformation of the cut and raised parts 51 to which flexibility is given. Alternatively, the putting may be made by sliding the attaching member 43 on the first metal plate 21 before the feeding line 42 is attached to the attaching member 43.
According to the structure mentioned above, the rear surface of the first metal plate 50A is flat except for the base end portion 42a of the feeding line 42 of the feeding component 40A. Thus, the feeding component 40A has no effect on the circuit board located on the rear surface of the first metal plate 50A regarding size, shape and/or mounting area.
Referring to
The feeding component 40B is mounted on the first metal plate 50A by engaging the catches 51a of the cut and raised parts 51 of the first metal plate 50A with the steps 434 of the feeding component 40B.
Engaging the cut and raised parts 51 with the steps 434 may be implemented by elastic deformation of the cut and raised parts 51 to which flexibility is given. Alternatively, the engaging may be made by sliding the attaching member 43 on the first metal plate 21 before the feeding line 42 is attached to the attaching member 43.
According to the structure mentioned above, the rear surface of the first metal plate 50A is flat except for the base end portion 42a of the feeding line 42 of the feeding component 40B. Thus, the feeding component 40B has no effect on the circuit board located on the rear surface of the first metal plate 50A regarding size, shape and/or mounting area.
While this invention has thus far been described in conjunction with the preferred embodiments thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners. For example, the engaging means are not limited to the locking hooks, hollows or steps mentioned above.
Number | Date | Country | Kind |
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2005-91304 | Mar 2005 | JP | national |
The present application is a Divisional Application of U.S. application Ser. No. 11/320,081 filed Dec. 28, 2005, which is claims priority to prior application JP 2005-91304, the disclosures of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | 11320081 | Dec 2005 | US |
Child | 11960362 | US |